From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp•fujitsu.com>
To: Glauber Costa <glommer@parallels•com>
Cc: netdev@vger•kernel.org, David Miller <davem@davemloft•net>,
Andrew Morton <akpm@linux-foundation•org>
Subject: Re: [PATCH] memcg/tcp: fix warning caused b res->usage go to negative.
Date: Tue, 10 Apr 2012 11:37:37 +0900 [thread overview]
Message-ID: <4F839CF1.5050104@jp.fujitsu.com> (raw)
In-Reply-To: <4F7F1091.9040204@parallels.com>
(2012/04/07 0:49), Glauber Costa wrote:
> On 03/30/2012 05:44 AM, KAMEZAWA Hiroyuki wrote:
>> Maybe what we can do before lsf/mm summit will be this (avoid warning.)
>> This patch is onto linus's git tree. Patch description is updated.
>>
>> Thanks.
>> -Kame
>> ==
>> From 4ab80f84bbcb02a790342426c1de84aeb17fcbe9 Mon Sep 17 00:00:00 2001
>> From: KAMEZAWA Hiroyuki<kamezawa.hiroyu@jp•fujitsu.com>
>> Date: Thu, 29 Mar 2012 14:59:04 +0900
>> Subject: [PATCH] memcg/tcp: fix warning caused b res->usage go to negative.
>>
>> tcp memcontrol starts accouting after res->limit is set. So, if a sockets
>> starts before setting res->limit, there are already used resource.
>> At setting res->limit, accounting starts. The resource will be uncharged
>> and make res_counter below 0 because they are not charged.
>> This causes warning.
>>
>
> Kame,
>
> Please test the following patch and see if it fixes your problems (I
> tested locally, and it triggers me no warnings running the test script
> you provided + an inbound scp -r copy of an iso directory from a remote
> machine)
>
> When you are reviewing, keep in mind that we're likely to have the same
> problems with slab jump labels - since the slab pages will outlive the
> cgroup as well, and it might be worthy to keep this in mind, and provide
> a central point for the jump labels to be set of on cgroup destruction.
>
Hm. What happens in following sequence ?
1. a memcg is created
2. put a task into the memcg, start tcp steam
3. set tcp memory limit
The resource used between 2 and 3 will cause the problem finally.
Then, Dave's request
==
You must either:
1) Integrate the socket's existing usage when the limit is set.
2) Avoid accounting completely for a socket that started before
the limit was set.
==
are not satisfied. So, we need to have a state per sockets, it's accounted
or not. I'll look into this problem again, today.
Thanks,
-Kame
next prev parent reply other threads:[~2012-04-10 2:39 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-29 7:01 [BUGFIX][PATCH 0/3] memcg: tcp memcontrol fixes KAMEZAWA Hiroyuki
2012-03-29 7:03 ` [PATCH 1/3] [BUGFIX] memcg/tcp : fix to see use_hierarchy in tcp memcontrol cgroup KAMEZAWA Hiroyuki
2012-03-29 9:14 ` Glauber Costa
2012-03-29 9:16 ` KAMEZAWA Hiroyuki
2012-03-29 7:07 ` [BUGFIX][PATCH 2/3] memcg/tcp: remove static_branch_slow_dec() at changing limit KAMEZAWA Hiroyuki
2012-03-29 10:58 ` Glauber Costa
2012-03-29 23:51 ` KAMEZAWA Hiroyuki
2012-03-30 6:18 ` Glauber Costa
2012-03-29 7:10 ` [BUGFIX][PATCH 3/3] memcg/tcp: ignore tcp usage before accounting started KAMEZAWA Hiroyuki
2012-03-29 9:21 ` Glauber Costa
2012-03-30 1:44 ` [PATCH] memcg/tcp: fix warning caused b res->usage go to negative KAMEZAWA Hiroyuki
2012-04-06 15:49 ` Glauber Costa
2012-04-10 2:37 ` KAMEZAWA Hiroyuki [this message]
2012-04-10 2:51 ` Glauber Costa
2012-04-10 3:01 ` Glauber Costa
2012-04-10 4:15 ` KAMEZAWA Hiroyuki
2012-04-11 2:22 ` Glauber Costa
2012-04-10 3:21 ` KAMEZAWA Hiroyuki
2012-04-13 17:33 ` Glauber Costa
2012-04-18 8:02 ` KAMEZAWA Hiroyuki
2012-04-18 16:32 ` Glauber Costa
2012-04-02 3:41 ` [BUGFIX][PATCH 3/3] memcg/tcp: ignore tcp usage before accounting started David Miller
2012-04-03 22:31 ` Glauber Costa
2012-04-09 0:58 ` KAMEZAWA Hiroyuki
2012-04-09 1:44 ` Glauber Costa
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